In the manufacture of containers comprising combinations of screw-type closures with associated containers, it often becomes necessary or desirable to determine the degree to which the threaded closure complies with applicable torque specifications. For example, in some situations, the torque with which a threaded closure is applied must be of a certain magnitude in order to properly seal the container so the closure does not become loose during shipment. This is especially critical if hazardous material is being shipped. Also, in the packaging of pharmaceutical products, since they can be toxic in the wrong dosages, dosage requirements are somewhat critical and it is often either required, or deemed desirable, to have a child-proof safety closure limiting access to the container contents. Such safety closures may, for example, comprise a threaded inner cap for being threaded directly to the finish of a container and an overlap loosely retractable relative to the inner cap. A user must push the outer cap axially onto the inner cap to engage a ratchet mechanism to be able to simultaneously turn the inner cap.
During the manufacture of products packaged in containers having threaded closures, the caps may be applied with a capping machine which must be adjusted from time to time to compensate for normal mechanical or component variations which may affect application of torque. Normally, periodic control checks are conducted on the packages being produced. During a particular production run, an operator may periodically remove a completed sample product to determine the degree of torque required to remove a threaded closure from an associated container. A removal torque which falls outside a predetermined range indicates the capping mechanism or other components of the manufacturing process must be adjusted or replaced.
There are known prior art devices and methods for effecting quality control torque tests of threaded closures to determine the amount of torque required to remove the closure from the threaded finish of the container. One of the standards of the industry is known as the Owens-Illinois Torque Meter manufactured by Secure Pak, Inc., Toledo, Ohio. There are also bench top torque measuring devices wherein the container is placed and squeezed to resist any rotational movement during the testing operation. The torque required to remove the associated closure is measured. To obtain the desired measurements the containers must be transported to and from the torque measuring devices. The manner in which the torque is applied varies from one operator to another. Consequently, torque data thus produced may be non-uniform and non-reliable in comparison to industry standards.
In certain situations, packages being used to transport hazardous materials are tested and approved by the Department of Transportation (DOT). The DOT has specific instructions and requirements for compliance to DOT standards associated with the shipment of such materials. In recent times, DOT has begun to audit and inspect the end users of these packages. The DOT has been requiring assurance from these end users that the closure torque stated by the end user in reply to a DOT question is accurate. If the end user cannot supply such assurance to the satisfaction of DOT, significant fines may be assessed. While, as discussed above, there are machines for measuring such closure torque, the machines known to the inventor are expensive, cumbersome to use, and not at all mobile whereby an end user or transport driver will not have easy access to such a device. At the present time, the inventor is not aware of any device that can expeditiously and accurately verify the closing torque of the containers in such a shipment.
Still further, some containers are closed by smooth-sided caps. With no ribbing or such to grab or hold on the outside of the closure, a mold maker cannot make an inverted mold of the closure to grab and hold it. The inventor is not aware of any device which both satisfies the above-mentioned requirements and which is amenable for use on a smooth-sided closure.